624 WHITE FT AI ferences in agreeableness have been shown to influence re Graziano. s respond to conflic by us tha rely o Overview of Studies er.Ro but not tho In this article we investigate (a)wbether agreeableness shifts ir igh in agrecable ecome more ag ve when primed with s is related to a n cialit to threat.(c)if shifts in y.high le hreat and a als high in agre perationto and of pe hin ndri haller M unta,Pan &1 2010 et al,2007 omprebensive understanding of the ce een threats o ,1999 A d we ex the ng one ions.abiding bye the desire s:and in respons dition Sc he agreeablene e nations.Study 2 explore tion,we sugge t that bothare that an individua oup size in threat resp Study 4 was a fielo Rat we expect tha if threat and a behavioral esponding so d to threat wit reats of vio cial behaviors.would help a pe ff Study 1:Nation-Level Threats of Violence and Agreeableness person to respond to sarch has demonstrated that threats of von cn dt hre factors that of violence trigg n strategies,thcm onship betw n threat and agreeab s:(a)the targets being should rep s and 1b) ciodevelopmental fa cople in co ed to the the face of threat.it w or beneficial.for a of chose to examin hould occur primarily toward m mbers of the ingroup.who may hreat of violence Indeed nast ch has found that militar and that publi f other rget of agreeabler the size of one's socia ions of inte ational threa inc 1950d2000ou small group sizes that advantage is reduced.As such.the size of Finally,military spending is an advantageous variable to examineferences in agreeableness have been shown to influence responses to threatening or distressing situations. Graziano, Jensen￾Campbell, and Hair (1996) found evidence that individuals low in agreeableness respond to conflict by using tactics that rely on asserting power over others, and Meier, Robinson, and Wilkowski (2006) reported that individuals low in agreeableness, but not those high in agreeableness, become more aggressive when primed with aggression words. Overall, these findings indicate that low agree￾ableness is related to a number of attitudes and behaviors that may facilitate aggression. Conversely, high levels of agreeableness have been linked to many attitudes and behaviors that can promote affiliation. Individ￾uals high in agreeableness prefer cooperation to competition, are willing to risk more to help others, are more prosocial, and have more harmonious relationships with others (Caprara, Alessandri, Di Giunta, Panerai, & Eisenberg, 2010; Graziano et al., 2007; Graziano, Hair, & Finch, 1997; Soldz & Vaillant, 1999). Agree￾ableness is also positively correlated with values related to social goals, such as fulfilling one’s social obligations, abiding by estab￾lished norms, avoiding disruption of relationships with others, concern for the welfare of others, and the desire to care for others (Roccas, Sagiv, Schwartz, & Knafo, 2002). The research reviewed thus far has linked threat to agreeable￾ness in two seemingly contradictory ways. In the current investi￾gation, we suggest that both are possible, depending on a combi￾nation of situational circumstances and individual differences. Moreover, we propose that agreeableness is not just an individual difference that moderates threat responding. Rather, we expect that agreeableness may actually shift in the face of threat. Such a response would serve a functional purpose: Shifts toward lower agreeableness, accompanied by shifts in corresponding so￾cial behavior, would incline a person respond to threat with ag￾gression or avoidance. Conversely, shifts toward greater agree￾ableness, and accompanying social behaviors, would help a person affiliate and aggregate with others. Given that shifts toward lesser or greater agreeableness prepare a person to respond to threat in very different ways, it seems improbable that threat will be linked to just one response or the other. Instead, it makes more sense for shifts in agreeableness to be functionally tuned to unique combinations of situational circum￾stances and individual differences. Here, we propose two factors that may critically moderate the relationship between threat and agreeableness: (a) the targets being considered as affiliation partners and (b) sociodevelopmental fac￾tors linked to the size of one’s social group. In the face of threat, it would not be useful, or beneficial, for a person to become more or less agreeable with everyone. As we explore in Studies 3, 4, and 5, shifts toward greater agreeableness should occur primarily toward members of the ingroup, who may offer physical and social support, but not necessarily toward mem￾bers of other groups, who may actually pose a treat. In addition to the target of agreeableness, the size of one’s social group might also influence threat responding. According to animal research, as group size increases, the survival advantages accrued through affiliation and aggregation also increase (Watt & Chap￾man, 1998). Thus, at large groups sizes, affiliation and aggregation are likely to be successful strategies for overcoming threat, but at small group sizes that advantage is reduced. As such, the size of one’s social group may influence whether a person responds to threat with affiliation. We explore this issue in Study 3. Overview of Studies In this article, we investigate (a) whether agreeableness shifts in response to threats of violence, (b) how psychological states and social behaviors associated with agreeableness—trust and proso￾ciality—might also shift in response to threat, (c) if shifts in agreeableness are target-specific, and (d) if individual differences in the size of one’s social group moderate the relationship between threat and agreeableness. Recent findings have linked disease threat to variations in the expression of personality characteristics both at the national level (Schaller & Murray, 2008) and in response to temporary, situa￾tional variation (Mortensen et al., 2010). To provide a similarly comprehensive understanding of the connection between threats of violence and agreeableness, we examined their relation at three levels of analysis—in mean national differences; in individual differences; and in response to temporary, situational conditions (both in the lab and in the field). Study 1 examined the correlation between threats of violence experienced at the national level and the agreeableness of individuals in those nations. Study 2 explored the correlation between individual differences in the perception of threats of violence and agreeableness. Study 3 experimentally manipulated threats of violence, examined changes in agreeable￾ness toward familiar and unfamiliar social groups, and assessed the role of social group size in threat responding. Study 4 was a field study using a real-world manipulation of threat and a behavioral measure of agreeableness— help directed toward ingroup members or outgroups. Returning to the national level in Study 5, we examined the correlation between threats of violence and another indicator of agreeableness—trust in various social groups. Study 1: Nation-Level Threats of Violence and Agreeableness Study 1 sought to test whether a relationship between threats of violence and agreeableness existed at the national level. Because past research has demonstrated that threats of violence can lead to both aggression and affiliation, there are two possible outcomes. If threats of violence trigger aggression strategies, then people in countries experiencing greater threat should report being less agreeable. However, if threats of violence trigger affiliation strat￾egies, then people in countries experiencing greater threat should report being more agreeable. To assess national threats of violence, we chose to examine military spending, a variable that has been linked to the type of intergroup hostility and conflict that fosters a national sense of threat of violence. Indeed, past research has found that military build-ups precede actual wars (Wallace, 1979) and that public support for higher military spending tends to increase as percep￾tions of international threat increase (Kriesberg & Klein, 1980). Moreover, a comprehensive analysis of all interstate conflicts between 1950 and 2000 found that military spending was signif￾icantly correlated with probability of actual conflict (Nordhaus, Oneal, & Russett, 2009) and that this relation survives controlling for a number of political, geographic, and economic variables. Finally, military spending is an advantageous variable to examine 624 WHITE ET AL. This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly